There is known, as a technique related to connection between an access point device for a wireless LAN and a wired LAN, a technique described in, for example, Japanese Patent Application Laid-Open No. 05-091093. The technique disclosed in the Japanese Patent Application Laid-Open No. 05-091093 is intended to provide a switch (6) connecting to one of two wired LAN transmission lines (9 and 10) in a connection unit (1) corresponding to an access point. With a configuration of this technique, if a fault occurs on the connected wired LAN transmission line, the connection is switched over to a connection to the other transmission line.